Add-On Display Module for Portable Computer

1. An add-on display module adapted to be attached to a primary display device of a portable computer for displaying an image signal transmitted from the portable computer, comprising: a mounting frame having a fixing means for attaching the mounting frame to a rear side of the primary display device of the portable computer; a secondary display device framed in the mounting frame; and means for electrically connecting the secondary display device to the primary display device, having a first connector provided on the primary display device of the portable computer and a second connector provided on the secondary display device; wherein the secondary display device is detachably attached on the rear side of the primary display device of the portable computer by the mounting frame and connected with the primary display device via the connecting means, so as to receive and display the image signal of the portable computer.

2. The add-on display module as claimed in claim 1 , wherein the fixing means of the mounting frame comprises a pair of side brackets formed at two opposite sides of the mounting frame for engaging with two opposite sides of the primary display device and thereby attaching the mounting frame and the secondary display device framed in the mounting frame to the rear side of the primary display device of the portable computer.

3. The add-on display module as claimed in claim 1 , wherein the fixing means of the mounting frame comprises at least one hooking member for hooking the mounting frame with the secondary display device framed therein onto the rear side of the primary display device of the portable computer.

4. The add-on display module as claimed in claim 1 , wherein the fixing means of the mounting frame comprises at least one projected portion, the second connector being mounted in the projected portion and the first connector being provided at an upper edge of the primary display device corresponding to the second connector, so that the mounting frame is attached to the rear side of the primary display device by connecting the second connector into the first connector.

5. The add-on display module as claimed in claim 1 , wherein the mounting frame has a width and a length substantially the same as those of the primary display device of the portable computer.

6. The add-on display module as claimed in claim 1 , wherein the first connector and the second connector are insertion-type connectors comprising a female connector and a male connector.

7. The add-on display module as claimed in claim 1 , wherein the first connector is an infrared emitting port and the second connector is an infrared receiving port.

8. The add-on display module as claimed in claim 1 , wherein the image signal shown on the secondary display device is the same as that shown on the primary display device of the notebook computer.

9. The add-on display module as claimed in claim 1 , wherein the image signal shown on the secondary display device is different from that shown on the primary display device of the notebook computer.